Firebase Core - Gradle Dependency Conflict

[adila...@gmail.com]

I have the following Gradle dependencies:

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])

    //Firebase dependencies
    implementation 'com.google.firebase:firebase-core:16.0.4'
    implementation 'com.google.firebase:firebase-ads:17.1.0'
    implementation 'com.google.firebase:firebase-iid:17.0.4'

    //Android SDK
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support:support-v13:28.0.0'
    implementation 'com.android.support:recyclerview-v7:28.0.0'
    implementation 'com.android.support:design:28.0.0'
    implementation 'com.android.support:palette-v7:28.0.0'
    implementation 'com.android.support:customtabs:28.0.0'

    //3rd Party Dependencies
    implementation 'pub.devrel:easypermissions:1.3.0'
    implementation 'com.google.code.gson:gson:2.8.5'
    implementation 'com.github.bumptech.glide:glide:4.8.0'
    annotationProcessor 'com.github.bumptech.glide:compiler:4.8.0'
    implementation 'jp.wasabeef:recyclerview-animators:2.3.0'
    implementation 'com.github.apl-devs:appintro:v4.2.3'
    implementation 'com.iarcuschin:simpleratingbar:0.1.5'
}

The main gradle is as follows:

dependencies {
    classpath 'com.android.tools.build:gradle:3.2.1'
    classpath 'com.google.gms:google-services:4.2.0'
}

As seen, All the firebase/gms libraries are latest. But the gradle gives me a warning that:

All gms/firebase libraries must use the exact same version specification (mixing versions can lead to runtime crashes). Found versions 17.1.0, 17.0.4, 17.0.2, 17.0.1, 16.2.2, 16.0.4, 16.0.3, 16.0.2, 16.0.1, 16.0.0. Examples include com.google.android.gms:play-services-ads:17.1.0 and com.google.firebase:firebase-iid:17.0.4 less... (Ctrl+F1)

There are some combinations of libraries, or tools and libraries, that are incompatible, or can lead to bugs. One such incompatibility is compiling with a version of the Android support libraries that is not the latest version (or in particular, a version lower than your targetSdkVersion.)

I tried using the 'play-services-ads' dependency instead of the 'firebase-ads'. Also tried adding the 'firebase-iid' dependency, but for no luck. I am not sure if this is relevant but if I see the Gradle console, I see this warning 'Warning:Failed to parse host www-proxy.idc.oracle.com'. 

How to resolve the dependencies correctly?